Aspidistra going downhill fast after 60-70 years!

karenbanks-64

Please help.....I have a large/heavy aspidistra which is between 60 and 70 years old.  Situated upstairs on the landing it has bloomed and grown new shoots until late last year when leaves started to yellow which as advised I cut off to avoid a 'waterfall' effect.  Whatever I do, its not happy and I really want to save it.  At moment, leaves are turning yellow again one after the other.  I've never repotted it and its planted directly into a large pot with no drainage holes (I bought it as a 50 year old some years ago).  Due to the sheer size and weight I decided to repot and reposition, but lockdown has prevented me so far....can anyone help.  Any advice at this stage would be greatly appreciated. Karen /